1. Motor Protection for this Millennium
Presented by
John S. Levine, P.E.
Levine Lectronics and Lectric, Inc.

2. Facts: Computers and the Internet are here to stay!
With microprocessors it is just as easy to give you everything verses several relays to do a job!
Corporations are downsizing personnel!
We are in a constant state of change!

3. Conclusions:
The equipment has to be able to help the few remaining personnel solve the problems even if that person is 1000 miles away !
Products need to be designed as families to reduce the cost.
Products are much more complex than 10 years ago!
We can not avoid the change!

4. Motor Failure Rates and Cost
Motor failure rate is conservatively estimated as 3-5% per year.
In Mining, Pulp and Paper industry motor failure rate is up to 12%.
Motor failure cost contributors:
Repair or Replacement.
Removal and Installation.
Loss of Production.
Rewind cost of High Voltage motor depends on terminal voltage, horsepower, number of poles and can vary from 5000 to 50000$ dollars.
Some facilities rule not to repair but replace low voltage motors up to 250HP.
Removal and Installation cost is about % unless motor is very big.
Loss of Production. This is hard to estimate, can be evaluated by downtime cost. Time to repair motors above 500hp is 2-3 weeks

5. Motor Management Relay
469 and 369
Motor Management Relay
Protection and management of medium voltage motors and driven equipment

6. Product Highlights
Inputs / Outputs
Motor Protection
Power Metering
Diagnostics
Communications / 469PC/369PC
Simulation

7. Product Highlights Comprehensive motor protection
Protection of motors with high inertia loads
Induction and Synchronous motors
Two speed motors
Differential protection (469), Input to 369
Reduced voltage start
RTU functions
Remote start/stop

8. CT and VT Inputs 3 phase CTs Typical wiring 1 amp 5 amp
3 differential CTs (469)
1 ground CT
Zero sequence
Residual
3 phase VTs
Open Delta
Wye
Typical wiring
Mention Dot orientation on CT’s and Pt’s.
Mention that you will discuss differential in next slide.
Core balance differential CTs
1 amp
5 amp

9. Differential in a Motor (469)B
The customer has protection for overcurrent with the CT’s and ground fault protection with the multilin 2001 to 1 CT or 50 to .025 ground fault Ct. Differential protection provides protection of a phase to phase leakage. On some big motors you will find CT’s in the motor junction box. This is what these are used for. You may also see differential protection for a line with 2 Ct’s. One at the substation and one at the load. This would protect the wire. C

10. CT Inputs Residual ground wiring Alternate differential wiring
If you do not have a ground fault Ct the residual ground wiring works well.
Summation of two CTs
provides a larger zone of protection
Observe polarity

11. Using Power Factor Correction Capacitors
CT’S
Contactor
Cap

12. RTD Inputs 12 RTDs, field programmable type
RTD wiring
12 RTDs, field programmable type
Independent trip and alarm settings
Trip voting
Feedback to thermal model
Programmable RTD name
Open sensor detection
Tell the customer to use 6 rtd’s for the stator, 2 on the motor bearing, 2 on the pump bearing, 1 on the pump casing, and 1 for ambient.
Trip voting requires 2 RTD’s to go high before a trip.
RTD protection will quadruple the protection on the motor. Use it!
The resistance in the wire can not be more than 25% of the RTD ohms. For a 10 ohm copper I can not have more than 2.5 ohms per wire.

13. Digital Inputs 9 digital inputs (469), 6 digital inputs (369)
pre-defined (Access, test-469, emergency, remote reset, starter status-469)
4 assignable (speed switch, load shed, pressure, vibration, tachometer, counter, general & programmable)
If you have a Synchronous Motor use must us a 52B contact to let us know the motor is still running. If the current goes below 5% we think the unit has turned off. This is why you will see so many starts in the statistical data.

14. Analog Inputs (469) 4 analog inputs (469) self powered or loop powered
Loop powered analog inputs
4 analog inputs (469)
self powered or
loop powered
Vdc
Assignable name
Min., max., & units
Block from start
Trip
Alarm
delay
We have a source of 24 VDC on terminal A22.

15. Output Relays 6 output relays (469), 4 output relays (369), Form C,
4 programmable analog outputs(469), option on 369
4-20 or 0-1 mA (as ordered-469) programmable on 369
29 programmable parameters
2 RS485 ports(469), 3 RS485 ports(369),
1 front panel RS232 port
22 front panel status indicators (469), 10 on 369
If using the remote RTD unit on the 369 you wire this to one of the ports.

16. Motor Protection Thermal Single line diagram Block starts
Short circuit / backup
Mechanical jam
Phase reversal
Unbalance
Undercurrent
Ground fault / backup
Differential
Acceleration
Stator/Bearing/Other
Ambient RTD
Single line diagram
Thermal model will be discussed in more detail in the next slide.
Block starts is number of starts/hour. This is a rolling window.
Do not use Short circuit to trip the contactor. Contactor is only designed to interrupt 5000 amps. Go to up stream breaker. Backup goes to the breaker a head of the up stream breaker if it fails.
Mechanical jam – give example of truck axle in Chipper. I do not want to wait 60 seconds to trip at 300% current. Trip in 10 seconds.

17. Thermal Model - Thermal Capacity Used
We will use the following model to aid in a better understanding of motor thermal modeling concepts. The motor’s thermal capacity, that is to say, the amount of heat energy the motor can hold, will be represented by the glass vessel. The lava like fluid filling the vessel will represent thermal energy or heat energy that has been absorbed by the motor.
We will use the following model to aid in a better understanding of motor thermal modeling concepts. The motor’s thermal capacity, that is to say, the amount of heat energy the motor can hold, will be represented by the glass vessel. The lava like fluid filling the vessel will represent thermal energy or heat energy that has been absorbed by the motor.
 The sources of thermal energy that will fill the vessel or heating the motor are:
 • Ambient temperature
 • Motor losses due to current unbalances and I squared T
Motor heating due to a start.
 Motor cooling will be represented by:
 •The vapour evaporating from the surface of the liquid when the motor is running or stopped will represent the motors ability to dissipate heat
 • the fan is representative of the additional cooling effect of the motor’s cooling system which is commonly a fan mounted on the motor shaft.
 With this model in mind lets proceed with our explanation of motor thermal modeling:
The thermal capacity that has been used is expressed as a percentage of the total thermal capacity of the motor and can be thought of as the amount of the vessel’s volume that has been filled with heat energy. If this imaginary vessel is full, 100% of the thermal

18. Thermal Model - Thermal Capacity Used
 The sources of thermal energy that will fill the vessel or heating the motor are:
Ambient temperature
Motor losses due to current unbalances and I squared T
Motor heating due to a start
capacity of the motor has been reached and any further increase will result in damage to the motor’s insulation. The motor insulation does not immediately melt. Rather, the rate of insulation degradation has reached a point where motor life will be significantly reduced if it continues to run under this condition.
Ambient temperature and I2T heating due to motor losses, starting current, and current unbalances start to fill the vessel with thermal energy when the motor current is above the motor’s full load current. Once the motor current drops to or below the motors full load current rating the thermal capacity used starts to drop. This can be imagined as the thermal energy slowly draining from the vessel. The rate at which the thermal energy is drained and the final level that it will drop to is a function of the motor data and load current which will be covered later in this section. The vessel is also emptied when the motor is stopped at a rate based on the stopped cooling time.

19. Thermal Model - Thermal Capacity Used
 Motor cooling will be represented by:
 • The vapour evaporating from the surface of the liquid when the motor is running or stopped will represent the motors ability to dissipate heat.
 • The fan is representative of the additional cooling effect of the motor’s cooling system which is commonly a fan mounted on the motor shaft.
The vessel is also emptied when the motor is stopped at a rate based on the stopped cooling time.

20. Motor Protection Standard Overload Curves 15 standard overload curves
1 custom curve (FlexCurve)
1 Voltage dependent curve (469)
Under/Over voltage
Reverse power
Underpower
Under/Over frequency
kvar, PF (Synch. motor)
Amps, kW, kvar, kVA demand alarms
Trip coil supervision (469)
Breaker failure
Incomplete sequence
Service Factor Protection
If you have to go into the service factor we now cut off the lower end of curve. Do not shift the curve. Example 100 amp FLA, Used at 110 amps, 6 times is 600 verses Voltage dependant will discuss on future slide
Trip coil supervision to monitor that coil is not open so that it will close when we tell it to close.

21. Hot / Cold Ratio = 15 sec/20 sec or .75
Cold Motor Curve
Hot Motor Curve
20 sec
15 sec
At 6X cold motor can go 20 seconds, hot 15 seconds.
6 X FLC

22. Thermal Model - Thermal Limit Curves
Relay overload curve

23. Thermal Bias Hot/Cold motor compensation
RTD and Unbalance Biasing
Hot/Cold motor compensation
RTD Thermal Bias
Min. temperature (40 C) / No biasing
Max. temperature ( Insulation rating) /Thermal capacity =100%
Mid point temperature and thermal capacity
Negative Sequence Current Bias
Accounts for excess rotor heating due to unbalanced voltages (skin effect - Induced current rotating in opposite direction at 2x line freq..)
Not accounted for by curves provided by motor manufacturer
Hot/Cold Compensation
Vertical line is Thermal Capacity Used. At 40 degrees C there is 0 contribution to the Thermal model. At 155 degrees there is 99% added to the thermal model. Under normal operation you are running around 130 degrees which is 15% thermal contribution. This is why you can stop a motor that as run 3 days straight at 100% current. Stop it and restart it.
Negative Sequence we must derate the motor. At 3% voltage unbalance you derate the motor 10%.

24. Voltage Dependent O/LCurve
Custom curve for running in overload
Minimum starting voltage
Minimum stall point
Min. accel. intersection point with custom curve
Maximum starting voltage
Maximum stall point
Max. accel. intersection with custom curve
SR469 dynamically shifts curve for all voltages
Use next slide to go into detail. Only need to use on large motors that trip durring starting because you are exceding the thermal damage curve.

25. 3 parts of the Curve 1) Locked Rotor 2) Acceleration 3) Running
Voltage dependant looks at the voltage as well as the current. Gives us more time to accelerate the motor without damaging the motor because it is turning so air is blowing over the motor and cooling it.
To determine the proper overload curve use example of soft start curve. At 200% need 110 seconds, at 300% need 32 seconds.
Motor Acceleration Curve
at 80% Voltage
Motor Acceleration Curve
at 100% Voltage

26. Metering and Monitoring
Phase amps
Differential amps
% load
Ground amps
% unbalance
Voltage
+/-kW (HP), +/-kvar, kVA
Wh, + varh, - varh PF
Frequency
Demand (A, kW, kvar, kVA and peak demand)

27. Metering and Monitoring
RTD temperatures
Speed RPM (tach. input)
4 analog inputs
Learned parameters
Acceleration
Starting current
Starting capacity
Max. RTDs
Min./Max. analog inputs
Mention Learned parameteres

28. Maintenance & Diagnostics
Statistical data on:
Number of trips
Type of trips
Number of motor starts
Number of running hours
Last 255 events recorded (time and date stamped)
Cause of last trip
Pre-trip data
All active alarms

29. Communications
You can tie to a PLC. We can tell you the modbus card for each manufacturer.

30. Communications
You can tie to a PLC. We can tell you the modbus card for each manufacturer.

31. Memory Map Example Group Address Description
Current Phase A Current
Phase B Current
Phase C Current
030D Phase A Differential
030E Phase B Differential
030F Phase C Differential
Each setpoint and actual value has an address assigned to it that you can go look at.

32. Free PC Software and Firmware
Windows based
Access all:
Actual Values
Setpoints
Status
Event records
Oscillography
Graphical trending
Setpoint programming
Setpoint files
Download updated firmware to Flash memory
Three things to mention.
Oscillography - Shows wave forms
Graphical Trending – replaces a paper chart recorder (PC attached required)
Event recorder - All trips and alarms can be date stamped and shown.
Explain Firmware to Flash memory.

33. Motor Setting Auto-Configuration
Motor Nameplate
Motor Temperature Data
System Configuration
Current Sensing
Voltage Sensing
Motor Starting Supervision
Three things to mention.
Oscillography - Shows wave forms
Graphical Trending – replaces a paper chart recorder (PC attached required)
Event recorder - All trips and alarms can be date stamped and shown.
Explain Firmware to Flash memory.

34. 369 Motor Settings Auto-Configurator Report
Motor Settings Auto-Config Report
Clearly Organized
Individual Setting Identified
Report identifies warnings and provides suggestions

35. Motor Health Report Single-click access to Motor Health Report
Reads event history, learned motor parameters, motor start data logger from 369
Applies basic analysis to key motor parameters – Red/Orange/Green results
Prepares summary report as PDF file with all key information presented
Built into EnerVista™ 369 Setup and included in EnerVista™ Launchpad

36. Motor Health Report – Motor Stop/Trip History
Histogram representation of motor stops and trips
Classified by stop and trip causes
Simplifies troubleshooting and analysis
Quickly identifies motor and system issues

37. Security Audit Trail – Complete Traceability
Patented Security Settings Report
Only motor protection relay on the market to include this feature
History of last 100 changes
When, # of changes made, method, who, etc.
NERC CIP Compliant

41. Thank you